Means for securing printing plates to their cylinders under tension



Feb. 2, 1954 ZIEBELL 2,667,834

T. R. MEANS FOR SECURING PRINTING PLATES TO THEIR CYLINDERS .UNDER TENSION Filed Nov. 2, 1951 a mum JJE'J 20 15 /4 E Fr. 7

INVENTO Z4 M/ 2 3\\r /3 A w ///////4 y Patented Feb. 2, 1954 MEANS FOR SEGURING PRINTKNG PLATES T THEKR CYLINDERS UNDER TENSION Theodore R. Ziebell, Milwaukee, Wis, assig'nor to C. B. Cottrell. & Sons Company, Westerly, R. 1., a corporation of Delaware Application November 2, 1951, Serial No. 254,565

7 Claims.

This invention relates to means for securing printing plates to their cylinders under tension.

In plate securing means used in high speed rotary presses where the plate hooks are propelled along the cylinder grooves to and from their plate engaging positions by worm gears car ried by the hooks and engaging the cylinder racks, the cylinder racks frequently become worn and broken because of the necessarily limited engagement of only one or two of the teeth of the worm gears with the teeth of the cylinder racks.

This invention is directed to plate tensioning means for overcoming these rack failures by providing a plate tension hook comprising coacting stationary and movable members; the stationary member having a row of teeth for extended engagement with the teeth of a cylinder rack to prevent endwise movement of the stationary member; the movable member, which carries the printing plate engaging jaw, being slidable along the stationary member to exert tension on the printing plate for securing it to its cylinder.

This invention is also directed to a plate tension hook having novel features of construction whereby the manually operated adjusting screw, which connects the stationary and movable members of the plate tension hook, is rotatably mounted against endwise movement in the movable member and has a screw threaded engagement with the stationary member.

This invention is also directed to a plate tension hook in which gearing is provided for operatively connecting the adjusting screw with a removable key or other suitabl instrument.

A practical embodiment of my invention is represented in the accompanying drawings, in which Fig. 1 represents a detail plane view showing a portion of a printing plate secured to its cylinder.

Fig. 2 represents a similar View on a much larger scale.

Fig. 3 represents a detail longitudinal section taken in the plane of the line 33 of Fig. 2;

Fig. 4 represents a detail cross section taken in the plane of the line 4-4! of Fig. 2;

Fig. 5 represents a detail cross section taken in the plane of the line 55 of Fig. 2

Fig. 6 represents a side View of a key suitable for use in operating the movable hook member 2 grooves l2 provided along their bottoms with toothed racks it.

The curved printing plate it is shown as provided with undercut recesses 15 in its back adjacent its marginal edges for the reception of the plate tension hook jaws to be hereinafter described.

The plate tension hook for securing the printing plate is on the cylinder H under tension is shown as comprising a stationary member It and a movable member il in which the stationary member is housed.

The stationary member I6 is shown as provided with a row of teeth 58 along its bottom for extended engagement with the teeth of the cylinder groove rack it to look the stationary member against endwisc movement along the cylinder groove 52 when the plate tension hook has been inserted into the said groove at the desired position along the same, adjacent the recesses l5 in the back of the printing plate i l.

The movable member ll of the plate tension hook carries a plate engaging jaw it for securing the plate on the cylinder under tension. This movable member H has a longitudinal bottom groove ll* which houses the stationary member it; the side walls of said groove slidably engaging the side walls of the stationary member.

The manually operated means for slidably holding the movable hook member il in its cylinder groove i2 is shown as a pair of double winged locks 2t, 25, mounted near the ends of the said movable member and arranged to be turned into and out of the small grooves 22 along the side walls or" the cylinder groove 52.

The turnable lock 2% is formed integral with the plate engaging jaw it. The turnable lock 2! is shown as having an angular bore 23 for receiving the larger shank 2 5 of a suitabl key 25 for turning the said lock into and out of its sliding engagement with the side grooves 2.

The turnable lock it of the combined jaw and lock it, 20 may be turned into and out of sliding engagement with the side grooves 22 by manually turning the jaw it. The usual spring pressed balls 26, 2t may be employed to frictionally engage the locks 2t, 2i to yieldingly hold them in their withdrawn and extended positions.

The manually operated means for sliding the movable hook member along the stationary hook member, which is housed therein, is constructed, arranged and operated as follows:

An adjusting screw 28 operatively connects the two hook members it, ll, the head of the said screw being rotatably mounted against endwise acezess movement in the movable member I I and the threaded shank of the said screw being passed through and having a screw threaded engagement with the stationary member I6 of the said hook within said bottom groove ll The adjusting screw 28 has integra1 therewith a bevel gear 29' which meshes with a bevel gear 30 whose shank is rotatably mounted in the enlarged portion of the axial bore 23 of the turnable lock 2|. The upper end of this axial bore 23 is made angular for receiving'the larger shank 24 of the key 25 for turning the lock 2| into and out of its sliding engagement with the side grooves 22. The bevel gear 30 is provided with a smaller axial bore 32 for receiving the smaller shank 33 of the key 25 which may be" inserted,v through the angular bore 3| for turningthe bevel gear 30.

In operation, the plate tension hooks are inserted into the cylinder grooves l2 in proper positions to cause the rows of teeth I8 of the stationary hook' member 6 to bring the plate engaging jaws l9 into position to be engaged with the recesses in the back of the printing plate Hi. The jaw [9 of each of the plate hooks may then be turned to cause its double winged lock to slidably engage the side grooves 22. The shank 24 of the key 25 may then be inserted into the angular bore 3] to turn the double Winged lock 2! to also slidably engage the side grooves 22. The shank 33 of the key 25 may then be inserted into the angular bore 32 of the gear Bil to turn it and its meshing gear 29, which is fast on the adjusting screw 28, and thereby cause the screw, because of its threaded engagement with the stationary hook member It, to slide the movable hook member ll along the stationary hook member E6 to cause the jaw l9 to engage the recess is for exerting tension upon the printing plate it to secure it firmly on the cylinder 5.

It will be understood that while the plate holding means is herein shown and described in connection with a curved printing plate and a spirally grooved cylinder, the plate holding means may be employed in connection with plates and their bases of any character within the scope of this invention.

It is evident that various changes may be resorted to in the construction, form and arrangement of the several parts without departing from the spirit and scope of this invention and hence it is not intended to be limited to the particular embodiment shown and described herein.

What I claim is:

1. A cylinder having spaced grooves, a printing platehaving recesses in its back, and a plate tension hook comprising a stationary member having means for locking it in a cylinder groove against endwise movement therein, a movable member having a longitudinal bottom groove housing the stationary member, a plate recess engaging tension jaw carried by the movable member, a screw located in said bottom groove and operatively connecting the two members, and a manually operated gearing for rotating the screw to slide the movable member along the stationary member housed therein in a direction to cause the tension jaw to secure the plate on the cylinder under tension.

2. A cylinder having spaced grooves, a printing plate having recesses in its back, and a plate tension hook comprising a stationary member having means for looking it in a cylinder groove against endwise movement therein, a movable member having a longitudinal bottom groove housing the stationary member, a plate recess engaging tension jaw carried by the movable member, a screw located in said bottom groove and rotatably mounted against endwise movement in the movable member and threaded into the stationary member, a-gear fast ons'aid screw, and a manually operated meshing gear carried by the movable member for rotating the screw to slide the movable member along the stationary member housed therein in a direction to cause the tension jaw to secure the plate on the cylinder under tension.

3, A cylinder having spaced grooves, a printing plate having recesses in its back, and a plate tension hook comprising a, stationary member having means for locking it in a cylinder groove against endwise movement therein, a movable member having a longitudinal bottom groove housing the stationary member and provided with two manually turnable locks for slidably holding the hook in its cylinder groove, a plate recess engaging tension jaw carried by one of the turnable locks, and a manually operated means operable through the other lock for sliding the movable member along the stationary member housed therein in a direction to cause the tension jaw to secure the plate on the cylinder under tension.

4. A cylinder having spaced undercut grooves provided with toothed racks, a printing plate having recesses in its back, and a plate tension hook comprising a stationary member having a row of teeth for extended engagement with one or" said racks to lock the stationary member against endwise movement in the cylinder groove, 2. movablemember having a longitudinal bottom groove housing the stationary member and provided with two manually turnable locks for slidably holding the hook in its cylinder groove, a plate recess engaging tension jaw carried by one of the turnable locks, and a manually operated means operable through the other lock for sliding the movable member along the stationary member housed therein in a direction to cause the jaw to secure the plate on the cylinder under tension.

5. A printing plate tension hook comprising a stationary member provided with means for looking it against endwise movement in a plate cyl inder groove, a movable member having a longitudinal bottom'groove housing the stationary member and provided with two manually turnable locks for slicla'bly holding the hook in its cylinder groove, a plate recess engaging'tension jaw carried by'one of said turnable locks, and means operable through the other lock for sliding the movablemember along the stationary member housed therein.

6. A printing plate tension hook comprising a stationary member provided with a I'0W'0fl7l31'l for looking it against endwise movement in a plate cylinder groove, a movable member having a longitudinal bottom groove hou'singthe stationary member and provided with two manually turnable locks for slidably holding the hook in its cylinder groove, aplate recess engaging tension jaw carried by one of said turnable locks; and means operable through the other lock for sliding the movable member along the stationary member housed therein;

7. A' printing plate tension hook comprising a movable member having a longitudinal bottom groove, a plate recess engaging tension jaw carried by the movable member, a stationary meniber housed in the said bottom groove and provided with a row of rack engaging teeth, and a manually operated screw located in said bottom groove and rotatably mounted in the movable member against endwise movement and having a screw threaded engagement with the stationary member for sliding the movable member along the stationary member housed therein.

THEODORE R. ZIEBELL.

References Cited in the file of this patent UNITED STATES PATENTS Number Number 6 Name Date Miehle Dec. 11, 1906 Andrews July 18, 1911 Pitt et a1 Aug. 3, 1920 Brugmann Mar. 1, 1927 Durham Nov. 31, 1939 Luehrs Sept. 3, 1946 Meyer Mar. 22, 1949 

